It’s all in the way you roll your wrist while holding the pan
Perfect crepe-making is all in the wrist, according to physics.
Using a computer simulation, two fluid dynamics researchers have devised a step-by-step guide for preparing perfectly flat crepes. Their strategy, described in the June Physical Review Fluids, involves tilting and rotating the frying pan in circles. Besides making picture-perfect pancakes, this technique might be useful for chocolate manufacturing, as well as tasks outside the kitchen, such as applying coatings to smartphone displays, solar cells or circuit boards.
“The motivation for this study literally comes from the kitchen,” says Edouard Boujo of École Polytechnique in Palaiseau, France.
One day, his colleague Mathieu Sellier was frustrated that all of his crepes turned out uneven. Sellier’s wife reminded him that, as a fluid dynamicist, he of all people should be able to solve this problem. Sellier, of the University of Canterbury in New Zealand, accepted the challenge and teamed up with Boujo to create a computer simulation of a crepe cooking in a pan.
The simulation accounted for the pan’s orientation and temperature, as well as the batter’s changing thickness as it cooks. Sellier and Boujo analyzed this simulation using a mathematical technique called adjoint optimization to discover the pan motion that maximized crepe uniformity and minimized the amount of effort needed to move the pan.
The process: After pouring batter into the frying pan, tilt the pan steeply so that most of the batter slides from the center to the rim. Then, rotate the pan in circles to spread the batter around, gradually decreasing the pan’s incline until it lies flat and the batter is cooked. Et voilà, a crepe as flawless as the laws of physics allow.
E. Boujo and M. Sellier. Pancake making and surface coating: Optimal control of a gravity-driven liquid film. Physical Review Fluids. Vol. 4, June 2019. doi: 10.1103/PhysRevFluids.4.064802.
E. Conover. Microwaved grapes make fireballs, and scientists now know why. Science News. Vol. 195, March 30, 2019, p. 5.
M. Temming. Here’s how to bend spaghetti to your will. Science News. Vol. 194, September 29, 2018, p. 5.
L. Hamers. Microwaved, hard-boiled eggs can explode. But the bang isn’t the worst part. Science News Online, December 7, 2017.